Not a virgin anymore, and tips for a newbie?

I'm new to the sex scene and I lost my virginity to someone who has a high sex drive. So obviously he's more experienced, but I need tips for someone who's inexperienced. There were a couple times where he lost interest, because I wasn't doing enough. I felt insecure, because how do I keep someone's interest when I don't know what I'm doing? Help please!?